Improvement in brakes for sewing-machines



J. W. JACOB.

l Sewing-Machine Brake. No. 110,140. Patented Dec. 13, 187()` Fa'gf Z.

m'r/vessfs /WYENTM gaz? 5w JAMES W. J-AOOB, OF 'JEFFESONVILLE INDIANA, ASSIGNOR -TO HIMSELF AND JOHN J. ODONNELL, OF SAME PLACE.

Letters Patent No. 110,140, dated December 1 3, 1870.

IMPROVEMENT IN BRAKES FOR SEWING-MACHINES.

The Schedule referred to in-these Letters Patent and making part: 'of the same.

Tojtll lwhom tt may concern Be it kpown that I, JAMES XV. J A0013, ot' J effersonville, in the county of Clarke and State of Indiana, have invented a new and useful Improvement in Sewing-Machine Brakes, of which.the following is 'aspecication, reference being had to. the accompanying drawing.

ANatalee and Objects of. the Intention.

The invention relates to that class of .stops or brakes for prevent-ing` the retrograde movement of sewingmachines which operate on the eccentric principle, the

impinging surface of the brake being at unequal distances from the axle upon which it moves, and so arranged that the surface of the brake comes iu'coutact with the balance-wheel ofthe machine Aiu such manner that the forward motion of the wheel is'uot -retarded, while the retrograde movement is prevented,

by the distance between the impiugiug surfaces and the axle upon which the brake swings being so rapidly increased, as the retrograde movement begins, that the lbalance-wheel is stopped almost at the inception of the motion.

The brake is adjustable, being secured in a vertical slot in a vertically-dependent bar opposite the balance-wheel of thc machine, and, as it is provided with a set-screw, canv be xed at any desired position. It may also he raised entirely clear of the wheel when not in use.

Description of the Accompany-ing Drawing.

Figure l is a side elevation of the invention, showing the same as applied. rThe dotted lines indicate the position of the brake when raised.

Figure 2 is 'a perspective view of the invention, showing the construction of the brake.

Figure 3 is a vertical central sectionv 'of the brake through the.dotted line in tig. 4.

Figure 4 is a view of' thc under side of the brake.

General Description.

In the accompanying drawing- Fig. 4represents the brake, which is constructed as lfollows: Y

The plates F, of' similar dimensions, are placed directly opposite each other, and are so formed that the distance between theconvex edge of the foot and the axle aperture AN increases from the heelR to the toe S of the plates, between which a piece or pieces of 1ubber,.ieather, or similar material, 'of the shape shown at iig. 3, is or are tirmly secured so that the edge of the material projects beyond the convex edges and adjacent parts ofthe plates F. Y

One of the plates is provided with a thumb-piece,

by means of which the brake can bc raised so as to clear theswheel WV, or lowered.

The brake is pivote-d to thevshoulder L on the sliding plate D, and, when the brake. is elevated, the brace H, which connects the plates F, comes iu contact with the upper portion of the curved surface ot' the shoulder, and the brake is thereby-retained in the elevated position.

The slidingplate I) is provided, on the opposite side to that onwhich the shoulder L is placed, with a rectangular slide, C, movingr` in thc slot B, wherein it is kept iu the desired position by means of a setscrew.

The sliding plate D should bc of such length that, when the brake is elevated and the contact of the bracc H with the shoulder L is sutl'icient to keep it iu such position, the toe of the brake will be prevented from passing into the slot B or the plate D may be 'dispensed with, and wheuthe brake is elevated the toe thereof` maycnter thc slot, and thus the brake he kept in an elevated position by it-s gravity preponderating in the-direction of the hanger A.

The sctfscrew E in this construction is secured to the reverse side. ot' the shoulder C.

The foot 'l of thc slotted bar or hanger A is rigidlyzsccured to the under side ot' the table of a sewingmachine, and 'the brake is adjusted in the slot Bso that its frictional surface comes in contact with' the' periphery of the whcclV.

Operation.

Vheu the foot T is attached to the under side o thetable of a sewingmachiue in the manner described, the brake may be lowered by means of the thumb l piece I, and the machine started without any obst-ruction from the brake, since, as the wheel \V`revolves, and its periphery` comes in cont-act with the frictioual surface of the heel of the brake, the distance between the axle N and the point of contact ofv the wheel and brake is not increased, and consequently there is no pressure upon the wheel and hcucc its movement is not retarded.

A retrograde movement of the wheel is accompanied with reverse results, as thereby thc distaucebetweeu the impiugiug surfaces and the axle N is at once iucreased, and such a pressure is exerted upon the pcriphery ofthe wheel that its motion is almost at once checked.

It`.\it bc desired tn opcratc the machine without permittingthc liictioual suri'ace'ot' the brake to come in contact with the wheel, it only necessary to elevate the brake unt-il the toe thereof` comes incontact with the plate D, in which posit-ion it'will remain.

C Za'ims.

What I claim as my invention, and desire to secure by Letters Patent, is-

l. The friction-brake, constructed substantially as vdescribed, in combination with and adjustable on the slotted hanger A, for the uses and purposes set forth.

2. n combination with the above, the thumb-piece I Vfor removing the'brztke from or bringing it in oon'- tact with the fly-wheel \V 

